Tone-arm adjustment.



S. HECHLER.

TONE ARM ADlUSTMENT APPLICATION FlLED NOV.2, 1917 1,952,007, PatentedOct. 15, 1918,

INVENTOR CXHECkZJ I SAMUEL HECHLEB, OF NEW! YORK, N. Y.

Tense-an ADJUSTMENT.

application filed November 2, 1917.

rl have invented a new and improved is a full, clear, and exactdescription. "his invention relates to sound recording air reproducinginstruments and has parti lar reference to tone arm attachments.

Among the objects of the invention is to provide a simple device wherebythe counter balancing effect on a tone arm may be easily variedaccording to various types of records that are being ,played and withoutany danger of destroying the musical eiiect.

With the foregoing and other objects in view the invention consists inthe arrangement and combination of parts hereinafter described andclaimed, and while the invention is not restricted to the exact detailsof construction disclosed. or suggested herein, still for the purpose ofillustrating a practical embodiment thereof reference is had to theaccompanying drawings, in which like reference characters designate thesame parts in the several 'iews, and in which- Figure 1 is a perspectiveview of a conventional oscillating tone arm having my improvementapplied thereto.

Fig. 2 is a vertical sectional view indicat ing more particularly therelation of my improvement to the known devices.

Fig. 3 is a horizontal section on the line 3-3 of Fig. 2; and

Fig. i is a modification of the adjustment means.

Referring now more particularly to the drawings 1 indicate at a rigidstationary, horizontal base having a socket flange 11 1n which is fittedthe ball portion 12 of a curved tone arm 13 adapted to carry at itssmaller or free end any suitable structure or type of sound box 14:.These parts are old and well known and illustrated only to show themanner of use or application of my improvement.

The base is provided with a central tubular hub or hearing 15 having avertical axis in which is journaled a vertical shank 16 or" a pivot rodor cross head 17 whose ends are supported in the diametricallyoppositeside walls of the larger or lower end'of the tone arm no anyusual or well known manner. A finger piece 18 1s rigidly connectedSpecification of Letters Patent.

ne-rirm r tdjustment, of which the follow- I Patented (lot. 15, 1918.

Serial No. 199,973.

to the cross head and extends rearwardly therefrom and in the samehorizontal plane. Since the cross head 17 is supported directly in thelower end of the tone arm it follows that the rotation of the cross headand its shank 16 willalways correspond to the rotation of the tone armaround the axis of the hub 15. The shank 16, however, is held in thebearing 16 and hence the cross head constitutes a horizontalpivotprovided for the vertical oscillation of the tone arm in practice.

In order to adapt the weight of the free end of the tone arm and thesound box carried thereby to the particular type or make of record beingplayed it has heretofore been proposed to provide an adjustable screwconnection for a counter balance spring 19, one end of the spring beingattached to the rear end of the finger 18 while the upper end of thespring is connected to one portion of the adjustable screw devices. Asordinarily made, however, the adjustment of the screw cannot be madeexpeditiously by the average user of the instrument, butonly in a shopor by an expert. Furthermore an attempt on the part of the average userto make the adjustment commonly results in the failure of his purposeand even in many cases in the disconnection of the screw connections,rendering the machine inoperative temporarily and calling for expertassistance.

By my improvement I provide a means for not only insuring delicacy ofadjustment for the spring 19 so as to suitably counter balance the tonearm at any time but also I provide a quick adjustment whereby the changeof the effective weight of the sound box on one standard type of recordsto another and totally difierent standard type of records may be madealmost i11- stantly by any user and without any danger whatever ofdisconnecting any part or disabling the instrument. To this end Iprovide a hollow boss 20 having a vertical aXlS, said boss being ineifect a hollow cylinder extending vertically through the rear portionof the bend of the tone arm and having its axis in alinement with therear end of the finger 18. The upper end of the boss 20 I is a completehorizontal circle except for a notch 21 formed in one side thereof adacent to which is a shoulder 22. At 23 I indicate a connector extendingdown through. the boss 20 and having the upper end of the spring 19secured to the lower end thereof at 24.

adapted to hear directly upon the upper end of the boss as indicated inFig 2 when the cficctivc Weight oithe sound box is be iii-- creased. A.lug extending downward: from the head parallel to the axis of connectorprojects at this time into the notch 21. ll hen the strength of thecounter balance spring 19 is to he increased so as to make the effectiveWeight of the SOHnd'bOX less for cooperation with a different type ofrecords/ the operator simply lifts up on the connector by grasping afinger piece 2? lifting the lug 28 out of the notch and swinging itaround the vertical axis of the connector so as to bring the point ofthe lug upon the shoulder the connector will be locked until theeti'ective weight of the sound box is to be increasedagain. It will thusbe seen that -with the counter balance spring extend ing between theconnector 23 and the finger piece 18 with the proper amount of tensionfor any standard type of records an adjustment of the spring to anystandard type of records may be easily effected by simply manipulatingthe finger piece 27.

Calling attention now more specifically to l i l it will be noted thatthe connector 23 may be in the form of a telescopic screw having asleeve portion-28 into which the upper threaded end of a bolt 29 isscrewed.

As indicated the sleeve portion may have a head 30 located within acountersunk open upper end of the head 25 so that by application of ascrew driver to the head 30 the effective length of the connector may heincreased or diminished for the salts of delithe upper end the connectoris a head 4 insane? delicate adjustment may be made through the rotationof the sleeve 28 independently of the lift of the head 25 and likewisethe lifting of the head will not vary the length of the bolt.

1 claim:

l. The combination with an oscillating tone arm, a base on which thetone arm 1S pivoted, and a counter balancing spring acting between thebase and the rear portion of the tone arm tending to lift the free endof the tone arm, of a connector between the spring and the tone armcomprising a bolt to the lower end of which the spring is 'connectcd, ahead secured to the outer end of the bolt, projecting finger means forlifting the head and bolt, and means to hold the head and bolt inelevated position.

2. The combination with an oscillating tone arm, a-hase in which thetonearm is pivoted, and a counter-balancing spring actinghetween thebase and the tone arm tending to lift the free end of the tone arm, of aconnector bolt to which said spring is connected a head secured to theouter end of the bolt and bearing squarely against the main portion ofthe tone arm in one posi: tion, and having a lu adapted to projectagainst the tone arin'w en the head and bolt lifted to increase thetension or" the i shrin sat hunt rincnnne,

